COleSafeArray / VARIANT memory leak? - c++

Question

I want to export a lot of (table) data to Excel. I'm developing on Windows Xp, Vs2005. I'm filling a COleSafeArray, which was initialized like this:
safeArray.Create( VT_VARIANT, 2, numElements ); // 2 dimensional, 30000 rows, 3 columns
Now the filling is really fast, but in TaskManager/Process Explorer/VMMap, it looks like some of the memory does not get released properly (VMMap still finds my dummy strings in the memory). I tried the tips (disabling BSTR caching) from the following pages, but had no success so far:
https://devblogs.microsoft.com/oldnewthing/20091127-00/?p=15883
http://blogs.msdn.com/larryosterman/archive/2004/09/28/235304.aspx
Is there still the caching taking place (I've set the environment variable OANOCACHE = 1), or is there something wrong with my code?
Note: This is part of a MFC dialog based non-unicode application.
//-----------------------------------------------------------------------------
template< typename _ValueType >
void setSafeArrayElement( const _ValueType& value,
const int row,
const int column,
COleSafeArray& safeArray
)
{
VARIANT variant;
VariantInit(&variant);
{
COleVariant oleVariant = value;
variant = oleVariant;
oleVariant.Detach();
}
long coordinates[2] = { row, column };
safeArray.PutElement( coordinates, &variant );
VariantClear(&variant);
}
//-----------------------------------------------------------------------------
#define XL_CELLTYPE_TEXT "#"
#define XL_CELLTYPE_DOUBLE2 "#'##0.00"
#define XL_CELLTYPE_DOUBLE3 "#'##0.000"
#define XL_CELLTYPE_DOUBLE4 "#'##0.0000"
#define XL_CELLTYPE_DOUBLE6 "#'##0.000000"
#define XL_CELLTYPE_DOUBLE8 "#'##0.00000000"
#define XL_CELLTYPE_NUMBER "0"
#define XL_CELLTYPE_NUMBER1000 "#'##0"
#define XL_CELLTYPE_DATE "TT.MM.JJJJ"
#define XL_CELLTYPE_GENERAL "Standard"
//-----------------------------------------------------------------------------
void CexcelTestDlg::OnBnClickedButton2()
{
const bool closeExcel = true;
const int rows = 30000;
const int columns = 3;
//AfxOleGetMessageFilter()->SetMessagePendingDelay( x );
AfxOleGetMessageFilter()->EnableNotRespondingDialog( FALSE );
AfxOleGetMessageFilter()->EnableBusyDialog( FALSE );
Excel11::_ApplicationPtr app;
Excel11::WorkbooksPtr books;
Excel11::_WorkbookPtr book;
Excel11::SheetsPtr sheets;
Excel11::_WorksheetPtr sheet;
app.CreateInstance( "Excel.Application" );
try
{
//app->Visible = VARIANT_TRUE;
app->Visible = VARIANT_FALSE;
app->Interactive = VARIANT_FALSE;
app->UserControl = VARIANT_FALSE;
app->ScreenUpdating = VARIANT_FALSE;
app->DisplayAlerts = VARIANT_FALSE;
books = app->GetWorkbooks(); // all open files
book = books->Add(); // add new file
sheets = book->Sheets; // all worksheets
try
{
COleSafeArray safeArray;
DWORD numElements[] = { rows, columns };
safeArray.Create( VT_VARIANT, 2, numElements );
// rename default worksheet
Excel11::_WorksheetPtr
sheet1 = sheets->GetItem(1);
sheet1->Name = "Blah";
// format columns
{
std::string coords = getExcelCoordinates( 0, 0 ); // getExcelCoordinates returns strings like "A1", "F23", ... (excel cell coordinates)
Excel11::RangePtr range = sheet1->Range[coords.c_str()][coords.c_str()];
range = range->EntireColumn;
range->NumberFormat = XL_CELLTYPE_TEXT;
coords = getExcelCoordinates( 0, 1 );
range = sheet1->Range[coords.c_str()][coords.c_str()];
range = range->EntireColumn;
range->NumberFormat = XL_CELLTYPE_DATE;
coords = getExcelCoordinates( 0, 2 );
range = sheet1->Range[coords.c_str()][coords.c_str()];
range = range->EntireColumn;
range->NumberFormat = XL_CELLTYPE_DOUBLE2;
}
// fill line by line
for( int row = 0; row < rows; ++row )
{
CString rowName;
rowName.Format( "%d", row + 1 );
// Text
CString v0 = CString( "Wusel Dusel " ) + rowName;
setSafeArrayElement( v0, row, 0, safeArray );
// Date
CString v1 = "11.12.1975";
setSafeArrayElement( v1, row, 1, safeArray );
// Number
double v2 = 123.45;
setSafeArrayElement( v2, row, 2, safeArray );
}
// export safearray to excel
if( rows )
{
const std::string cellCoordTopLeft = getExcelCoordinates( 0, 0 );
const std::string cellCoordBottomRight = getExcelCoordinates( rows-1, columns-1 );
Excel11::RangePtr range = sheet1->Range[ cellCoordTopLeft.c_str(), cellCoordBottomRight.c_str()];
COleVariant vtOptional((long)DISP_E_PARAMNOTFOUND,VT_ERROR);
// export the whole safeArray contents to excel
range->PutValue( vtOptional, COleVariant( safeArray ) );
}
// optimize column widths
Excel11::RangePtr cells = sheet1->Cells;
cells->Select();
cells->EntireColumn->AutoFit();
Excel11::RangePtr singleCell = sheet1->Range["A1"]["A1"];
singleCell->Select();
// clear safeArray
VARIANT* varPtr = 0;
try
{
// Get a pointer to the elements of the array
// and increments the lock count on the array
safeArray.AccessData((LPVOID*)&varPtr);
for( int i = 0; i < rows * columns; ++i )
{
VARIANT& vp = varPtr[i];
VariantClear( &vp );
}
//decrement lock count
safeArray.UnaccessData();
}
catch (COleException *pEx)
{
AfxThrowOleDispatchException(1003, _T("Unexpected Failure in FastSort method"));
pEx->Delete();
}
//safeArray.DestroyData(); //???
//safeArray.DestroyDescriptor(); //???
safeArray.Clear();
}
catch( std::exception& err )
{
MessageBox( err.what() );
}
if( closeExcel )
{
book->Close( VARIANT_FALSE ); // close the file
app->Quit(); // close Excel instance
}
else
{
app->Visible = VARIANT_TRUE;
app->Interactive = VARIANT_TRUE;
app->UserControl = VARIANT_TRUE;
app->ScreenUpdating = VARIANT_TRUE;
app->DisplayAlerts = VARIANT_TRUE;
}
app.Release();
}
catch( _com_error& err )
{
CString s(err.Description().GetBSTR());
MessageBox(s);
}
}